The causes and solutions of crack formation of the check valve body casting in the pipeline

- Nov 13, 2017 -

In fact, the common check valve body castings in the pipeline system may have many different types of defects. Such as valve body cracks, air holes, slag inclusion and so on. Among them, the crack is more common. This is because in the casting process of this valve , it is easy to be affected by many different factors. Let's analyze the main reasons.

Analyzing from the experience, the appearance of the cracks in these check valve body castings mainly includes two cases. One is due to the cracks formed in the casting process. These castings are usually shipped with defects due to the failure without a hundred-percent inspection at the factory, or improper inspection methods. Another kind of crack belongs to the ageing crack.

Normally, these check valve body castings are treated with a casting process and require a period of one to two years for natural aging to release the internal stress. However, in some cases, with the rapid increase in the number of orders, the failure time is not fully guaranteed, so some castings will still remain a part of the stress. Thus, in the later use, the ageing cracks will be produced under the combined action of these residual stresses and the thermal stress produced during use.

So, is there any better way to deal with this crack problem of the check valve body castings? In fact, for this situation, it is necessary to combine the actual casting process of the valve and consult with the manufacturer about the repair welding, heat treatment process, and in accordance with the requirements of the process.